To investigate the antisickling potential of various agents on deoxygenated hemoglobin S, we have used the assay developed by Hofrichter, Ross and Eaton which monitors gelation kinetics via turbidity changes at 800 nm and measures solubility using ultracentrifuge sedimentation. The antisickling effect as measured by this assay has been determined for the amino acids, some dipeptides and several aromatic compounds. The aromatic amino acids, and phenylalanine analogs have been found to inhibit the gelation of deoxyhemoglobin S and hence may indicate a potential class of therapeutic anti-sickling agents. This project will be expanded to other compounds including oligopeptides in a continuing effort to study the surface interactions of deoxyhemoglobin S. BIBLIOGRAPHIC REFERENCE: Noguchi, C.T. and Schechter, A.N.: Effects of amino acids on gelation kinetics and solubility of sickle hemoglobin. Bioch. Biophys. Res. Com. 74, 637-642 (1977).